1. Field
The present invention relates generally to database management systems and, more particularly, to the reporting of performance effects of recovery time in database management systems.
2. Description of the Related Art
Conventional database systems, such as Oracle's relational database management system (RDBMS), permit an administrator to specify a recovery time within which the system is to recover from a system crash. In general, there is a tradeoff between the recovery time and the run-time operational performance of the database system. Typically, the smaller the recovery time, the more total physical writes (I/Os) the database system needs to perform. The database system needs to perform more physical I/Os to reduce the amount of data it needs to recover after a system crash.
For example, Oracle's RDBMS will dynamically adjust the physical I/O pace to meet the specified recovery time. Typically, a short recovery time comes at the expense of an increased number of runtime physical I/Os, which in turn reduces the system's throughput or performance.
One drawback to determining an acceptable tradeoff between recovery time and system performance is that a system administrator has to use conventional trial-and-error approaches to determine an appropriate recovery time setting. The administrator has to specify a recovery time, execute the database system for a typical workload, and document the effect of the recovery time on the system's performance. The administrator goes through several iterations of this process using different recovery times in order to determine a recovery time that satisfies both the recovery time requirement and the system performance.
What is desired is a system and method that documents the effects of multiple recovery times on system performance without requiring multiple iterations of the iterative trial-and-error process of specifying a recovery time and measuring its affect on system performance.